The present invention generally relates to a method and apparatus for communication. More particularly, embodiments of the present invention relate to methods and apparatus for communication between serving mobile location centers (SMLCs) in the packet-switched domain.
Location-based services are an increasingly important aspect of communication networks. In the United States, for example, the Federal Communications Commission (FCC) requires certain wireless networks to provide the ability to identify the location of mobile devices in the network. Throughout the world, applications are being developed to support consumer and business location-based services in wireless networks.
Several location methods are standardized to position mobile devices. For example, Enhanced Observed Time Difference (E-OTD) and Assisted GPS (A-GPS) are two positioning methods widely used in digital mobile communication systems. Several new network nodes have been introduced to support positioning methods in wireless networks. In the radio sub system, serving mobile location center (SMLC) and location measurement unit (LMU) nodes are used to support positioning. LMUs make radio measurements to support one or more positioning methods. Data from an LMU, including timing and assistance data, are provided to an associated serving mobile location center (SMLC). Each SMLC may be an integrated function in a radio base station system or it may be a stand-alone network element within a radio access network. Each SMLC manages the overall coordination and scheduling of resources required to provide location-based services of each mobile device in the area. The SMLC may control a number of LMUs to help locate each mobile device in the area served by the SMLC. A public land mobile network (PLMN) may include a number of SMLCs.
Each SMLC in the PLMN may need to request or provide location information to other SMLCs in the PLMN. Currently, this sharing of location information between SMLCs is performed using direct connections between SMLCs (e.g., using Signaling System 7 or “SS7”) connections, or using circuit-switched connections through a base station subsystem (e.g., through signaling transfer points, or “STPs”). Unfortunately, if there is no direct SS7 or links to an STP which would allow this intercommunication between two SMLCs, there is currently no way that the two SMLCs could share location information. If a network operates in a packet-switched mode, it is possible that no direct SS7 link or link to an STP will be available between two SMLCs.
One particular network architecture which is being developed and which does not currently support packet-switched intercommunication between SMLCs is the network architecture resulting from the merger of global system for mobile communication (GSM)/Enhanced Data rates for Global Evolution (EDGE) (“GERAN”) with universal mobile telecommunications system (UMTS). This merger is part of a migration toward third-generation wireless systems which merge aspects of GERAN high-speed transmission with aspects of the UMTS core networks. The alignment of GERAN with UMTS to provide a high-speed, high-bandwidth communications network is supported by standards activities governed by the “3rd Generation Partnership Project” (3GPP™), whose standards are located at www.3gpp.org. Unfortunately, as described above, existing work in aligning GERAN with UMTS does not support communication between SMLCs in a network using a packet-switched protocol to pass location information from one SMLC to another.
It would be advantageous to provide a method and apparatus that overcame the drawbacks of previous systems. In particular, it would be desirable to provide a system, method, apparatus, means and computer program code for allowing communication between two SMLCs in a packet-switched mode. It would further be desirable to provide such communication to allow the sharing of location information between SMLCs.